Pea Protein - Composition and Amino Acids
Peas can be processed into pea protein through various processing steps. To produce pea protein, the peas are first cleaned and ground in a dried state, resulting in pea flour 1. The flour is then hydrated. Pea starch and fibers can now be extracted. The protein fraction undergoes another purification process (coagulation) and is then dried in a multi-stage spray dryer.
Pea protein is gluten-free.
Pea Protein as a Source of Protein
The most important plant protein fraction is the storage protein globulin (65 to 80%), followed by two other fractions - albumin and glutelin 3 4. The fractions consist of various proteins composed of different amino acids.
Limiting Amino Acids
Plant-based protein sources generally lack one or more essential amino acids 7. They are referred to as incomplete proteins in scientific literature. For example, pea protein contains less tryptophan as well as the sulfur-containing amino acids cysteine and methionine 8 9. For this reason, it is recommended to combine pea protein with other vegan protein powders such as rice protein, lupine protein, and/or hemp protein.
If one or more amino acids are supplied to the body in smaller amounts in order to form peptides and proteins, those already supplied await the missing ones in an amino acid pool 10. Therefore, it is not necessary to combine different sources of protein. The absence of certain amino acids can be avoided with a balanced diet.
The PDCAAS method can be used to determine the protein quality of a specific food 11. The obtained value provides information on the extent to which the food can meet the amino acid needs of humans and how well the food can be digested. The maximum value is 1.0. For pea flour, which contains high levels of protein, it is 0.69 12. The resulting pea protein concentrate has a PDCAAS value of 0.73, and the pea protein isolate has a value of 0.82 13 14.
Good Digestibility and Low Allergenic Potential
Pea protein is easy to digest and does not cause discomfort in the digestive tract 15.
Compared to other protein sources such as soy protein or wheat protein, pea protein has a very low allergenic potential 16. From this perspective, it is better suited than other protein powders.
Pea Protein vs. Whey
Results from a 2015 study with 161 participants (137 successfully completed the study) indicate that pea protein can be used as an alternative to whey protein, as it is also rich in branched-chain amino acids (BCAAs) including valine, isoleucine, and leucine. BCAAs play an important role in muscle protein synthesis. Pea protein, in conjunction with the strength training program, increased muscle mass to a greater extent than animal-based protein powder and the placebo (maltodextrin) 17. The biceps muscle thickness increased by 20.2% (± 12.3%) with pea protein, 15.6% (± 13.5%) with whey protein, and 8.6% (± 7.3%) with the placebo. Muscle strength also increased. However, no statistical differences were observed between the groups. The study lasted for 12 weeks with 3 training days per week. Protein powder and placebo were taken twice daily, 25g each time, before and after training. The researchers suggest that pea protein is particularly suitable for those starting or returning to strength training.
Pea Protein Suitable for Diabetics
Another study examined the benefits of pea protein and other pea components on food intake, blood sugar levels, and appetite in young men 18. The participants' blood sugar levels remained lower than usual. There were no changes in appetite or overall food intake. The results suggest that pea protein and other pea components, as ingredients in food, can improve glycemic control (regulation and maintenance of blood sugar levels within the normal range).
Pea proteins Increase Satiety
Study findings indicate that pea proteins increase the feeling of fullness 19. The proteins have a promising benefit on reducing short-term food intake.
Lower Cholesterol Levels
In addition, a study showed that pea protein, along with soluble fiber, has a cholesterol-lowering benefit, similar to lupine protein 20. After consuming bars containing pea protein and oat fiber for 4 weeks, cholesterol levels were reduced by 4.7%. Similarly, consuming pea protein with apple pectin resulted in a 6.4% reduction.
Using Pea Protein
The easiest way to use pea protein is by incorporating it as an ingredient in protein shakes or smoothies.
Due to the functional properties of pea protein (solubility, water and fat binding capacity, and foaming), it can be used in the production of baked goods, soups, and snacks such as protein bars 21. Pea protein can also be used in the production of meat substitute products 22 23.
To improve digestion, digestive enzymes are often added to multi-component protein powders. They increase the presence of amino acids in the blood. 24.